Dependence of transport property of graphene nanoribbon on contacts: Electron-hole symmetry and conductance at the Dirac point

► We confirm general predictions for the transport through graphene nanoribbon (GNR) for specific geometries. ► Electron-hole symmetry depends sensitively on the structure of contact and GNR/contact interface. ► Electron-hole symmetry breaks in armchair graphene nanoribbon (AGNR) in the presence of odd-numbered ring at the interface. ► The unique momentum for maximal transmission is determined by the scattering between quantum wire and AGNR. ► The conductance at Dirac point is independent of the structure of contact with dense modes around Dirac point.